Mark Scheme (Result s)
Summer 2007
GCE
GCE Chemistry (6244) Paper 01
Edexcel Limited Registered in England and Wales No 4496750 Registered Office: One90 High Holborn, London W
General Guidance on Marking
Examiners should look f or qualit ies t o reward rat her t han f ault s t o penalise. This does NOT mean giving credit f or incorrect or inadequat e answers, but it does mean allowing candidat es t o be rewarded f or answers showing correct applicat ion of principles and knowledge.
Examiners should t heref ore read caref ully and consider every response: even if it is not what is expect ed it may be wort hy of credit .
Crossed out work should be marked UNLESS the candidate has replaced it with an alternative response.
Using t he mark scheme The mark scheme gives you:
an idea of t he t ypes of response expect ed how individual marks are t o be awarded t he t ot al mark f or each quest ion
examples of responses t hat should NOT receive credit .
Candidat es must make t heir meaning clear t o t he examiner t o gain t he mark. Make sure t hat t he answer makes sense. Do not give credit f or correct words/ phrases which are put t oget her in a meaningless manner. Answers must be in t he correct cont ext .
1 / means t hat t he responses are alt ernat ives and eit her answer should receive f ull credit . 2 ( ) means t hat a phrase/ word is not essent ial f or t he award of t he mark, but helps t he
examiner t o get t he sense of t he expect ed answer.
3 [ ] words inside square bracket s are inst ruct ions or guidance f or examiners.
4 Phrases/ words in bold indicat e t hat t he meaning of t he phrase or t he act ual word is essential t o t he answer.
5 ecf / TE/ cq (error carried f orward) means t hat a wrong answer given in an earlier part of a quest ion is used correct ly in answer t o a lat er part of t he same quest ion.
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E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K 1 . (a ) (i ) M g 2 + (g ) (+ ) O 2 - (g ) if s ta te s y m b o ls m is si n g If 2 e i n c lu d e d i n b o x (1 ) (i i) 1 H ✁ (E n th a lp y o f) f o rm a ti o n ( o f M g O ) (1 ) 2 H ✁ (E n th a lp y o f) a to m is a ti o n ( o f M g ) (1 ) 3 H ✁ 1 st p lu s 2 n d e le c tr o n a ff in it y ( o f O ) O R 1 st a n d 2 n d e le c tr o n a ff in it y ( o f O ) (1 ) R e c o g n is a b le a b b re v ia ti o n su c h a s “ E A ” f o r e le c tr o n a ff in it y . (3 ) (i ii ) LE H f ✂ ✂ ✂ ✂ ✂ ✂ ✂ ✂ ✄ ☎ ✄ ✆ ) 657 ( ) 249 ( ) 2186 ( ) 150 ( 602 O R (L E = ) -(+ 6 5 7 )-(+ 2 4 9 )-(+ 2 1 8 6 )-(+ 1 5 0 )+ (-6 0 2 )( 1 ) (L E = ) -3 8 4 4 ( k J m o l -1 ) (1 ) C o rr e c t a n sw e r o n ly w it h n o w o rk in g ( 1 m a x ) D o u b li n g e le c tr o n a ff in it y a n d / o r a to m is a ti o n v a lu e s sc o re s (0 ) a n y i n c o rr e c t si g n i n a lg e b ra ic e x p re ss io n ( 0 ) (2 )2 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (b ) (i ) T h e e le c tr o n s a ro u n d t h e i o d id e i o n a re d ra w n to w a rd s th e m a g n e si u m i o n (M g 2 + ) p o la ri se s (I io n ) “ d is to rt io n ” i f c le a rl y l in k e d to t h e i o d id e i o n “ M g i o n ” “ I io n ” O R “ io d in e i o n ” A n y r e fe re n c e t o a to m s o r m o le c u le s e .g . “ M g p o la ri se s… .. ” “ io d in e / I/ I2 i s p o la ri se d ” W ro n g p o la ri sa ti o n e .g . “ m a g n e si u m i o n i s p o la ri se d ” “ I p o la ri se s M g 2 + ” (1 ) (i i) R a d iu s/ si z e ( o f io n s) (1 ) c h a rg e ( o n i o n s) (1 ) D is ta n c e b e tw e e n i o n s O R S u m o f (i o n ic ) ra d ii O R T y p e o f c ry st a l st ru c tu re O R M a d e lu n g c o n st a n t “ C h a rg e d e n si ty ” “ a to m ic r a d iu s” (2 ) (i ii ) L e ss ( e x o th e rm ic ) (1 ) c o v a le n t c h a ra c te r (s tr e n g th e n s la tt ic e ) ( 1 ) M a rk e a c h a sp e c t in d e p e n d e n tl y S m a ll e r O R m o re e n d o th e rm ic O R L e ss n e g a ti v e O R L o w e r T h e o re ti c a l v a lu e b a se d o n p u re ly / 1 0 0 % i o n ic m o d e l H ig h e r/ g re a te r A n y i m p li c a ti o n o f m a g n e si u m io d id e b e in g t o ta ll y c o v a le n t (2 )
3 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (c ) (i ) E n th a lp y c h a n g e w h e n 1 m o l o f g a se o u s io n s (1 ) is d is so lv e d s u c h t h a t fu rt h e r d il u ti o n c a u se s n o fu rt h e r h e a t c h a n g e ( 1 ) IG N O R E “ st a n d a rd c o n d it io n s” M a rk e a c h a sp e c t in d e p e n d e n tl y E n e rg y o r h e a t “ A d d e d t o w a te r” / ” re a c ts w it h w a te r” i n st e a d o f “ d is so lv e d ” Is d is so lv e d t o f o rm a n in fi n it e ly d il u te s o lu ti o n O R Is d is so lv e d i n a la rg e / e x c e ss / in fi n it e a m o u n t o f w a te r A n y i m p li c a ti o n o f a n e n d o th e rm ic p ro c e ss e .g . e n e rg y r e q u ir e d “ … .1 m o l o f g a se o u s a to m s” J u st “ h y d ra te d ” J u st “ c o m p le te ly h y d ra te d ” (2 )
4 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (i i) E IT H E R ✁ ✂ ✄ ✁ LE SOLN H H ( ) HYD H ✁ (1 ) E x p re ss io n q u o te d o r c o rr e c tl y u se d i n a t le a st o n e o f th e c a lc u la ti o n s b e lo w SOLN H ☎ ) 1920 ( ) 2874 ( 4 ✆ ✝ ✆ ✆ ✞ MgSO kJ( 954 ✟ ✠ ) 1 ✡ mol (1 ) SOLN H ☛ ) 1360 ( ) 2374 ( 4 ☞ ✟ ☞ ☞ ✠ BaSO kJ( 1014 ✟ ✠ ) 1 ✡ mol ( 1 ) E n th a lp y o f so lu ti o n o f M g S O4 l e ss e n d o th e rm ic / m o re e x o th e rm ic / m o re n e g a ti v e t h a n f o r B a S O4 , so M g S O4 m o re s o lu b le t h a n B a S O4 ( o r re v e rs e a rg u m e n t) (1 ) O R (b o th ) la tt ic e e n e rg ie s a n d h y d ra ti o n e n th a lp ie s d e c re a se f ro m M g S O4 t o B a S O4 ( o r d o w n g ro u p ) (1 ) (b u t) l a tt ic e e n e rg ie s c h a n g e l e ss (1 ) ✁ ✂ ✄ ✁ LE SOLN H H ( ) HYD H ✁ (1 ) st a te d i n w o rd s o r sy m b o ls so ✌ Hso ln l e ss e x o th e rm ic / m o re e n d o th e rm ic / m o re p o si ti v e f o r B a S O4 s o l e ss s o lu b le O R s o ✌ Hso ln m o re e x o th e rm ic / m o re n e g a ti v e / le ss e n d o th e rm ic f o r M g S O4 s o M g S O4 m o re s o lu b le (1 ) A n sw e r o n ly w it h n o w o rk in g ( 1 ) A n sw e r o n ly w it h n o w o rk in g ( 1 ) “ T h e h y d ra ti o n e n e rg ie s d e c re a se f a st e r… .. ” J u st “ so lu b il it y / ✌ Hso ln d e p e n d s o n a b a la n c e b e tw e e n l a tt ic e a n d h y d ra ti o n e n e rg ie s” (-)5 0 0 a n d ( -) 5 6 0 s ta te d w it h o u t fu rt h e r e x p la n a ti o n J u st “ so lu b il it y / ✌ Hso lu ti o n d e p e n d s o n a b a la n c e b e tw e e n l a tt ic e a n d h y d ra ti o n e n e rg ie s” (4 ) (T o ta l 1 7 m a rk s)
5 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K 2 . (a ) ( 1 ) (1 ) A n y c o m p re ss e d f o rm u la e e .g . C2 H5 B r O R C H3 C H2 B r A n y c o m p re ss e d f o rm u la e e .g . C H3 C O N H2 O R (2 )
6 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (b ) A c c e p t n a m e s o r fo rm u la e , b u t ig n o re c o rr e c t o r in c o rr e c t c o n d it io n s S te p A : N H3 (1 ) Ig n o re s ta te o r d il u ti o n o r so lv e n t fo r a m m o n ia S te p B : K2 C r2 O7 (1 ) a n d H 2 S O4 (1 ) N .B . o n ly a w a rd t h e a c id / H2 S O4 m a rk i f a c o rr e c t (o r a n e a r-m is s) o x id is in g a g e n t g iv e n S te p C : P C l5 O R S O C l2 O R P C l3 ( 1 ) S te p D : P2 O5 O R P4 O1 0 ( 1 ) S te p E : L iA lH 4 ( 1 ) “ H y d ro c h lo ri c a c id ” / ” H C l” i n st e a d o f “ H2 S O4 ” C r2 O7 2 - a n d H + ( 2 ) O R C rO 4 2 - a n d H + ( 2 ) O R A c id if ie d d ic h ro m a te i o n s (2 ) O R A c id if ie d K2 C r2 O7 (2 ) O R a c id if ie d d ic h ro m a te (( V I) ) (1 ) O R K M n O4 (1 ) a n d H 2 S O4 ( 1 ) O R a lk a li n e K M n O4 (1 ) th e n a c id if y ( a c c e p t a n y a c id ) ( 1 ) C2 H5 O H a n d N a O R H 2 a n d N i / P t/ P d ( c a ta ly st ) O R L it h a l In c o rr e c t o x id a ti o n n u m b e r fo r d ic h ro m a te (V I) C rO 4 2 - a lo n e ( 0 ) H y d ro c h lo ri c a c id / H C l w it h K M n O4 ( 0 ) In c o rr e c t o x id a ti o n n u m b e r fo r m a n g a n a te (V II ) N a B H4 ( 0 ) (6 )
7 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (c ) (i ) (s u b st it u te d ) a m id e O R ( N -s u b st it u te d ) a m id e O R s e c o n d a ry a m id e O R 2 ✂ a m id e P o ly a m id e a m in e (1 ) (i i) N H (C H2 )6 N H C (C H2 )4 O C O p e p ti d e l in k N H C O (1 ) R e st o f m o le c u le a n d c o n ti n u a ti o n b o n d s (1 ) 2 n d m a rk i s C Q o n a p o ly a m id e b e in g d ra w n CONH (2 ) (d ) L o ss o f sm e ll : ✁ ✁ ✄ ☎ 3 2 3 2 2 3 NH CH CH H NH CH CH (1 ) R e tu rn o f sm e ll :
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H
NH
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2 2 2 3 3 2 3 ✆ ✝ ✆ ✞ ✟ O R C H3 C H2 N H3 C l + N a O H ✄ C H3 C H2 N H2 + H 2 O + N a C l ( 1 ) H C l a s a r e a c ta n t a n d ✠ ✁ Cl NH CH CH 3 2 3 a s p ro d u c t (c h a rg e s a re n o t re q u ir e d ). C H3 C H2 N H3 + + N a O H ✄ C H3 C H2 N H2 + H 2 O + N a + ( 1 ) (2 ) (T o ta l 1 3 m a rk s)8 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (a ) D o n o t w o rr y a b o u t g e n e ra l sh a p e o f th e c u rv e , th e s c o ri n g p o in ts a re : S ta rt in g p H ~ 1 a n d fi n is h in g p H b e tw e e n 9 a n d 1 1 ( 1 ) V e rt ic a l a t 2 5 c m 3 (1 ) V e rt ic a l ra n g e : a t le a st t h re e p H u n it s in t h e r a n g e 3 t o 8 e .g . p H r a n g e 3 t o 6 O R 3 t o 7 O R 3 t o 8 O R 4 t o 7 O R 4 t o 8 O R 5 t o 8 ( 1 ) (d o n o t n e e d t o s ta rt / fi n is h o n w h o le n u m b e rs ) M id d le o f v e rt ic a l p H r a n g e b e tw e e n 4 a n d 6 ( 1 ) p H r a n g e 3 t o 5 (4 )
9 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (b ) B ro m o c re so l g re e n In d ic a to r( s) C Q o n g ra p h [ c h e c k t a b le o n q u e st io n p a p e r] M o re t h a n o n e i n d ic a to r fo r e x te n d e d v e rt ic a l re g io n s (1 ) (c ) p H c h a n g e a ro u n d e q u iv a le n c e p o in t to o s m a ll O R p H c h a n g e s o v e r to o b ig a v o lu m e (1 ) fo r a s h a rp c o lo u r c h a n g e o f in d ic a to r ( 1 ) [I f sa y a m m o n ia i s a s tr o n g b a se o r e th a n o ic a c id i s a st ro n g a c id , o r b o th , (0 o u t o f 2 )] T o o s m a ll a v e rt ic a l (r e g io n ) O R n o v e rt ic a l (r e g io n ) O R n o p o in t o f in fl e x io n O R n o s u d d e n c h a n g e i n p H O R n o s tr a ig h t se c ti o n N o s h a rp / c le a r/ p re c is e e n d p o in t O R v e ry s m a ll r a n g e o v e r w h ic h in d ic a to r c h a n g e s c o lo u r N o s u it a b le i n d ic a to r O R N o “ e a sy ” c o lo u r c h a n g e (2 ) (T o ta l 7 m a rk s)
1 0 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (a ) H C O O C H H C H H H (1 ) (b ) e st e r (1 ) (c ) (i ) M o le s: C 2 H5 O H : 3 .7 5 ( 1 ) M o le s: H C O O C2 H5 : 2 .5 0 a n d m o le s H2 O : 2 .5 0 ( 1 ) fo r b o th (2 ) (i i) ] ][ [ ] ][ [ 5 2 2 5 2 OH H C HCOOH O H H HCOOC Kc O b v io u sl y r o u n d b ra c k e ts “ ( )” (1 ) (i ii ) 485. 0 75. 3 485. 0 50. 0 485. 0 50. 2 485. 0 50. 2 ✁ ✁ c K ( 1 ) M u st h a v e c le a rl y d iv id e d m o le s o f e a c h c o m p o n e n t b y 0 .4 8 5 f o r 1 st m a rk e .g . [H C O O C2 H5 ] = [ H2 O ] = 5 .1 6 ( m o l d m -3 ) a n d [ H C O O H ] = 1 .0 3 ( m o l d m -3 ) a n d [ C2 H5 O H ] = 7 .7 3 ( m o l d m -3 ) = 3 .3 3 ( 1 ) st a n d a lo n e m a rk IG N O R E s ig .f ig s. 75. 3 50. 0 ) 50. 2( 2 ✂ ✄ c K 33. 3 o n ly s c o re s (2 ) i f it i s st a te d t h a t V c a n c e ls e it h e r h e re o r in ( iv ) If ] [ 2 O H o m it te d i n ( ii ), t h e n a n sw e r ✄ c K 0 .6 4 7 m o l -1 d m 3 (2 ) b u t th is w il l g iv e ✄ c K 1 .3 3 m o l -1 d m 3 w it h V o m it te d f ro m c a lc u la ti o n (1 ) 1 st m a rk i f 4 8 5 u se d a s V i n e x p re ss io n (2 ) (i v ) N o , (a s) e q u a l n u m b e rs o f m o le s o n b o th s id e s O R v o lu m e s c a n c e l O R m o l d m -3 c a n c e l O R u n it s c a n c e l O R c ro ss in g o u t u n it s to s h o w t h e y c a n c e l “ e q u a l p o w e rs / m o le s o n b o th si d e s” O R “ p o w e rs c a n c e l” M a rk C Q o n c K e x p re ss io n i n ( ii ) “ c o n c e n tr a ti o n s c a n c e l” (1 )
1 1 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (d ) (i ) (a s re a c ti o n ) e n d o th e rm ic (1 ) Kc d e c re a se s ( 1 ) n u m e ra to r in q u o ti e n t (h a s to ) d e c re a se O R d e n o m in a to r in q u o ti e n t (h a s to ) in c re a se O R f ra c ti o n ( h a s to ) d e c re a se ( 1 ) y ie ld o f H C O O C2 H5 d e c re a se s (1 ) E x o th e rm ic i n b a c k w a rd d ir e c ti o n ( o r w o rd s to t h a t e ff e c t) If s ta te e x o th e rm ic i n f o rw a rd d ir e c ti o n , 1 m a rk o n ly ( o u t o f 4 ) fo r C Q “ in c re a se i n K c ” (4 ) (i i) n o e ff e c t a s c a ta ly st s d o n o t a ff e c t ( th e v a lu e o f) K O R n o e ff e c t a s c a ta ly st s d o n o t a ff e c t th e p o si ti o n o f e q u il ib ri u m O R n o e ff e c t a s c a ta ly st s d o n o t a ff e c t t h e y ie ld O R N o e ff e c t a s c a ta ly st s in c re a se t h e r a te o f th e f o rw a rd a n d b a c k w a rd r e a c ti o n s e q u a ll y / to t h e s a m e e x te n t O R n o e ff e c t a s c a ta ly st s o n ly i n c re a se t h e r a te O R n o e ff e c t a s c a ta ly st s o n ly a lt e r th e r a te “ n o e ff e c t” c a n b e s ta te d o r im p li e d IG N O R E a n y r e fe re n c e s to a c ti v a ti o n e n e rg y J u st “ c a ta ly st s in c re a se r a te ” (1 ) (T o ta l 1 3 m a rk s)
1 2 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K IG N O R E s ta te s y m b o ls t h ro u g h o u t th is q u e st io n . (a ) (i ) N a2 O + H 2 O 2 N a O H .. ✁ ✂ OH Na 2 O R .. ✁ ✂ ✄ OH Na 2 2 M u lt ip le s e .g . 2 N a2 O + 2 H2 O 4 N a O H (1 ) (i i) io n ic G ia n t io n ic O R e le c tr o v a le n t (1 ) (b ) (i ) 4 3 2 10 4 4 6 PO H O H O P ☎ ✆ O R 4 3 2 5 2 2 3 PO H O H O P ✄ M u lt ip le s (1 ) (i i) c o v a le n t ‘m o le c u la r c o v a le n t’ ‘s im p le c o v a le n t’ ‘c o n v a le n t’ O R ‘ g ia n t c o v a le n t’ O R d a ti v e c o v a le n t (1 ) (c ) b a si c ( o x id e s) t o a c id ic ( o x id e s) ( 1 ) b o th w o rd s n e e d e d IG N O R E r e fe re n c e s to A l2 O3 IG N O R E r e fe re n c e s to a m p h o te ri c c h a ra c te r o f A l2 O3 m e ta ll ic c h a ra c te r (o f th e e le m e n ts ) d e c re a se s (1 ) IG N O R E “ a c ro ss g ro u p ” i f u se d i n st e a d o f “ a c ro ss p e ri o d ” m e ta l to n o n -m e ta l T h e e le m e n ts c h a n g e f ro m b a si c t o a c id ic (2 )
1 3 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (d ) (i ) O H CO 2 2 ☎ ✁ ✂ 3 HCO H O R C O2 + 2 H2 O ☎ H 3 O + + H C O3 - C O2 + H 2 O ☎ 2 H + + C O3 2 - O R O H CO 2 2 ☎ 3 2 CO H ☎ H + + H C O3 - O R O H CO 2 2 ☎ 3 2 CO H ☎ 2 H + + C O3 2 - “ ✄ ” i n st e a d o f “ ☎ ” J U S T O H CO 2 2 ☎ 3 2 CO H (1 ) (i i) O H Pb H PbO 2 2 2 ✆ ✝ ✆ ✞ ✞ O R O H NO Pb HNO PbO 2 2 3 3 ) ( 2 ✆ ✝ ✆ (1 ) ✟ ✟ ✠ ✡ ✡ 2 4 2 ) ( 2 OH Pb O H OH PbO O R 4 2 2 ) ( 2 OH Pb Na O H NaOH PbO ✠ ✡ ✡ O R P b O + 2 N a O H ✄ N a2 P b O2 + H 2 O ( 1 ) fo rm a ti o n o f ☛ 4 6 ) (OH Pb O R 6 4 ) (OH Pb Na P b O w it h o th e r a c id s A n y e q u a ti o n s w it h P b O2 (2 )
1 4 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (e ) In c re a se s a s E IT H E R o x id e s a c id ic a t th e t o p o f th e g ro u p ( 1 ) a m p h o te ri c a t b o tt o m o f g ro u p ( 1 ) [a m p h o te ri c m u st b e s ta te d f o r th e 2 n d m a rk ] O R a to m s b e c o m e l a rg e r (1 ) (s o ) m o re e a si ly l o se e le c tr o n s O R h a v e l o w e r io n is a ti o n e n e rg ie s O R m o re e a si ly f o rm p o si ti v e i o n s (i n c o m p o u n d s) (1 ) [a ll o w 2 n d m a rk e v e n i f n o s p e c if ic r e fe re n c e h a s b e e n m a d e t o a to m s] [N .B . M a rk in g c a n n o t a ll o w p o in ts t a k e n f ro m b o th t h e E IT H E R a n d O R a rg u m e n ts t o g e th e r] O x id e s m o re b a si c d o w n g ro u p 1 ( o u t o f 2 ) O R o x id e s le ss a c id ic d o w n g ro u p 1 ( o u t o f 2 ) a to m s h a v e m o re s h ie ld in g / sh e ll s/ e n e rg y l e v e ls O R “ (o u te r) e le c tr o n s fu rt h e r fr o m n u c le u s” [n o n e e d t o r e fe r to a to m s in t h is c a se ] J u st “ in c re a se s” o n i ts o w n ( 0 ) O R “ in c re a se s” fo ll o w e d b y i n c o rr e c t ju st if ic a ti o n ( 0 ) J u st “ m o re e le c tr o n s” O R “ th e e le m e n ts b e c o m e l a rg e r” (2 ) (T o ta l 1 1 m a rk s)
1 5 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K 6 . (a ) (i ) OH CH CH CH 2 2 3 (1 ) R e d u c ti o n O R n u c le o p h il ic a d d it io n (1 ) IG N O R E h e te ro ly ti c OH CH H C 2 5 2 O R f u ll s tr u c tu ra l fo rm u la e .g . OH CCC H H H H HHH OR CCC H H H H HHH OH R e d o x “ N u c le o p h il ic r e d u c ti o n ” OH H C 7 3 (2 )
1 6 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (i i) C H3 C H2 C O OH (1 ) o x id a ti o n O R r e d o x (1 ) C2 H5 C O O H O R C H3 C H2 C O O H O R C H3 C H2 C O2 H O R C 2 H5 C O O H O R C 2 H5 C O2 H C2 H5 i n st e a d o f C H3 C H2 O R f u ll s tr u c tu ra l fo rm u la e .g . OR CC H H H HH C O OH CC H H H HH O C OH “ o x id is a ti o n ”
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-O
C
2H
5C
O
-OR
(2 )1 7 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (i ii ) N C OH CH CH CH ) ( 2 3 (1 ) n u c le o p h il ic a d d it io n ( 1 ) b o th w o rd s n e e d e d IG N O R E “ h e te ro ly ti c ” CN OH CH H C ) ( 5 2 O R CN OH CH CH CH ) ( 2 3 O R f u ll s tr u c tu ra l fo rm u la e .g . OR CC H H H HH C OH CN H CC H H H HH C H O H CN (2 ) (b ) (i ) MgBr H C Br H C Mg 5 2 5 2 ✁ ✂ IG N O R E c h a rg e s C2 H5 B rM g C2 H5 M g I (1 ) (i i) D ry e th o x y e th a n e O R d ry e th e r IG N O R E r e fe re n c e s to I2 O R h e a t (1 )
1 8 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K (c ) (i ) W it h p ro p a n o n e : S tr u c tu re : (C H3 )2 C (O H )C H2 C H3 (1 ) N a m e : 2 -m e th y lb u ta n -2 -o l O R 2 -h y d ro x y -2 -m e th y lb u ta n e ( 1 ) IG N O R E p u n c tu a ti o n C2 H5 i n l ie u o f C H2 C H3 O R th e f u ll s tr u c tu ra l fo rm u la e .g . O R C Q s tr u c tu re p ro v id e d i t is a te rt ia ry a lc o h o l C Q n a m e p ro v id e d t h a t it i s a te rt ia ry a lc o h o l OH H C 11 5 (2 )
1 9 E X P E C T E D A N S W E R A C C E P T R E J E C T M A R K W it h b u ta n a l: S tr u c tu re : 3 2 2 2 3 ) ( CH CH OH CH CH CH CH (1 ) N a m e : h e x a n -3 -o l ( 1 ) th e f u ll s tr u c tu ra l fo rm u la e .g . OR C C C C C C HH H H H H H H H H HH H O H C C C C C C HH H H H H H H H H HH H O H C Q s tr u c tu re p ro v id e d i t is a s e c o n d a ry a lc o h o l h e x a n e -3 -o l C Q n a m e p ro v id e d t h a t it i s a s e c o n d a ry a lc o h o l OH H C 13 6 (2 ) (i i) C O H (g ro u p i n b u ta n a l) is p la n a r (1 ) a tt a c k e d ( w it h e q u a l p ro b a b il it y ) fr o m t w o d ir e c ti o n s (1 ) M a rk e a c h a sp e c t in d e p e n d e n tl y u n le ss r e fe re n c e m a d e t o c a rb o c a ti o n s e tc B u ta n a l/ th e m o le c u le / it i s p la n a r O R B u ta n a l/ th e m o le c u le / it i s li n e a r R e fe re n c e s to c a rb o c a ti o n s O R c a rb o n iu m i o n s O R P la n a r in te rm e d ia te s O R SN 1 m e c h a n is m s sc o re s (0 o u t o f 2 ) (2 ) (T o ta l 1 4 m a rk s)
